The assembly of seat belt retractor mechanisms usually involves the attaching of the rewinding spring portion of the mechanism to a shaft extending from a seat belt storage spool through a frame onto which the spool is journaled. As the typical rewind spring is wound in a flat coil, the attachment of the spring to the shaft is usually done by placing the inner end of the spring is a slot in the shaft. The outer end of the rewind spring is attached to a housing which is usually mounted to the frame by means of snap pins or similar arrangements.
Prior to the housing being snapped to the frame, the rewind spring must be wound to exert the proper bias on the belt storage spool. In order to wind the spring, the spring housing must be rotated relative to the frame. As the snap pins, or other means by which the housing attaches to the frame, extend outwardly from the housing to the frame, the rotating of the housing to wind the spring necessitates holding the housing away from the frame during the winding process. The separation of the housing from the frame during the winding frequently results in the inner end of the spring frequently becoming disengaged from the shaft of the storage spool. The disengagement results in the rapid unwinding of the spring and the necessity for repeating the winding process.
The efficiency of the assembly of the retractor mechanism would be greatly simplified if the housing could be held directly against the frame during the winding process. As the end of the storage spool shaft normally abuts the inside wall of the housing when the housing is snapped onto the frame, the ability to hold the housing against the frame during the winding process would prevent the inner end of winding spring from disengaging the slot in the shaft extending from the storage spool.
Accordingly, it is the principal object of this invention to facilitate the quick assembly of a seat belt retractor mechanism.
It is an additional object of this invention to prevent the disengagement of the retractor mechanism spring from the belt storage spool during the assembly process.
It is a final object of this invention to improve retractor mechanism housings to simplify the assembly of the portions of the seat belt retractor mechanism in the housings.